Although ectopic gastric mucosa is often mentioned as a source of upper esophageal adenocarcinoma, few such cases have actually been documented. We report two cases and offer a review of the literature. Ectopic gastric mucosa in the upper esophagus is a relatively common congenital condition, but the risk of malignant transformation is extremely low. Ectopic gastric mucosa should be distinguished from Barrett''s esophagus, an acquired condition with a well-documented predilection for developing adenocarcinoma.